How to reproduce:
1. Create a new project
2. Select Game Tab > Aspect Ratio dropdown > 5:4
3. Select Scene Tab > 2D button
4. Select Main Camera GameObject
5. Zoom out the Scene View until Camera Gizmos is seen
6. Notice that Camera Gizmos remains unchanged in the Scene View

Expected result: Camera Gizmos is changed in the Scene View on the Aspect Ratio change
Actual result: Camera Gizmos remains unchanged in the Scene View on the Aspect Ratio change

Reproducible with: 2019.3.0a8, 2019.3.0a11
Not reproducible with: 2017.4.31f1, 2018.4.5f1, 2019.1.13f1, 2019.2.0f1, 2019.3.0a7